Work vehicles for example, lift trucks, typically have a lift mast pivotally mounted on the front end of the vehicle. The lift mast is usually nested between the front wheels of the vehicle and closely adjacent to the vehicle so that the load carrying capacity of the vehicle for a given vehicle weight, is maximized. U.S. Pat. No. 3,915,324, dated Oct. 28, 1975 to Donald A. Green et al., U.S. Pat. No. 3,999,873, dated Dec. 28, 1976 also to Donald A. Green et al., U.S. Pat. No. 4,126,209 dated Nov. 21, 1978 to Robert D. Higgins et al., and U.S. Pat. No. 4,100,988 dated July 18, 1978 to Harold V. Hildebrecht teach mounting arrangements for placing a lift mast between the front wheels of the vehicle and in close proximity to the front of the frames so that the load moment about the center of gravity of the vehicle is kept at a minimim which maximizes the load carrying capacity of the vehicle.
None of the above patents provide a mounting arrangement for connecting a high visibility mast to the vehicle. A high visibility mast is one which has substantially no obstructions disposed between the inner uprights of the mast at a location adjacent to the line of sight of the operator and one in which the inner uprights are tightly nested adjacent respective outer uprights and a substantial distance apart from one another. The reason that none of the above-mentioned patents employ a high visibility mast is that the space available between the vehicle wheels and the design and construction of the mast itself does not permit the use of the mounting arrangements disclosed in the above-noted references. Also, the mounting arrangements of the above-listed patents would not be readily accessible for installation and removal purposes due to the limited amount of space available.
In order to be able to connect or disconnect the lift mast to and from the vehicle, it is necessary to have adequate access to the shaft or pin which pivotally connects the lift mast to the vehicle. None of the mounting arrangements of the prior art provide a mounting arrangement in which the mounting pin or shaft can be successfully removed in this environment. This is primarily due to the fact that the lift jack of the high visibility mast encroaches on the space which was previously usually open and accessible. None of the references make provisions for removal of the mounting shaft in an environment wherein the lift jacks are nested closely adjacent the uprights and not centered between the spaced apart pairs of uprights.
Therefore, it is necessary to provide a pivotal mounting arrangement for a high visibility mast wherein the envelope of the mounting arrangement is kept to a bare minimum and facilitates removal of the mast pivot shaft from connection with the vehicle and/or lift mast.